The cable manufacturer should specify a method. On a recently completed installation we used non-metallic cable ties and attached the cables to the wire mesh and rebar. This was the method recommended by that cable manufacturer. KB
#39267 - 06/16/0412:51 PMRe: Heat Trace cables in concrete.
Take a look at NEC ARTICLE 426 for Fixed Outdoor Electric Deicing and Snow-Melting Equipment ... If this article applies, there are installation requirements that also call attention to the instructions that come with the product.
It would be appreciated if you could take some pictures and post them here for us to see.
Joe Tedesco, NEC Consultant
#39268 - 06/16/0406:53 PMRe: Heat Trace cables in concrete.